Nasal cannula

ABSTRACT

A nasal cannula comprising: a base portion defining a gas passageway and one or more nozzles defining a second gas passageway in gaseous communication with the first gas passageway for directing a therapeutic flow of gas to a user&#39;s nares. The nasal cannula may include one or more sensors for measuring the properties of gas within a user&#39;s nares. The nozzle may be a nasal insert that is inserted into the user&#39;s nares; recesses or grooves are provided for preventing sealing of the nasal insert with the nare. The nozzle may be shaped to avoid insertion into the user&#39;s nares, thus preventing sealing with the nares. A stop may be positioned between two nozzles to engage a user&#39;s columella and prevent the nozzles from inserting into the user&#39;s nares. Elongate extensions are provided for inserting into the user&#39;s nares and supporting sensors for measuring gas properties therein.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 60/716,776, filed Sep. 12, 2005, of which thecontents are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

Nasal cannulas are used to deliver respiratory gases for therapeuticeffect, including O₂ therapy, treatment for sleep apnea, and respiratorysupport. However, treatment with certain types of nasal cannulas may belimited by the lack of information available on important treatmentparameters. These parameters include information regarding the gaseswithin the user's upper airway, such as pressure, flow rate, and carbondioxide build up. These and other data may be useful in judging theefficacy of treatment as well as for controlling and monitoringtreatment.

In addition, prior art nasal cannula designs (especially those designedfor neonatal oxygen therapy) may undesirably create a seal with theuser's nares, which may have detrimental effects on the user's health.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the accompanying drawing figures, whichare not necessarily drawn to scale.

FIG. 1 is a perspective view of a nasal cannula according to aparticular embodiment of the invention.

FIG. 2 is a perspective view of a nasal cannula according to a furtherembodiment of the invention.

FIG. 3 is a perspective view of a nasal cannula according to anotherembodiment of the invention.

FIG. 4 is a perspective view of a nasal cannula according to yet anotherembodiment of the invention.

FIG. 5 is a front perspective view of a nasal cannula according to afurther embodiment of the invention.

FIG. 6 depicts a cross section of a nasal insert of a nasal cannulaaccording to a particular embodiment of the invention.

FIG. 7 depicts a cross section of a nasal insert of a nasal cannulaaccording to a further embodiment of the invention.

FIG. 8A is a front perspective view of a nasal cannula according toanother embodiment of the invention.

FIG. 8B is a rear perspective view of the nasal cannula shown in FIG.8A.

FIG. 8C is a perspective cross-sectional view of the nasal cannula shownin FIG. 8A.

FIG. 9 is a perspective view of a nasal cannula according to a furtherembodiment of the invention.

FIG. 10 is a perspective view of a nasal cannula according to anotherembodiment of the invention.

FIG. 11 is a perspective view of a nasal cannula according to a furtherembodiment of the invention.

FIG. 12 is a perspective view of a nasal cannula according to yetanother embodiment of the invention.

FIG. 13 illustrates an embodiment of a nasal cannula in use on apatient, according to one embodiment of the invention.

FIG. 14 illustrates another embodiment of a nasal cannula in use on apatient, according to a further embodiment of the invention.

DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION

The present inventions now will be described with reference to theaccompanying drawings, in which some, but not all embodiments of theinventions are shown. Indeed, these inventions may be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will satisfy applicable legal requirements. Likenumbers refer to like elements throughout. For example, elements 130,230, 330, 430, 530, 830, and 930 are all nasal inserts according tovarious embodiments of the invention.

Overview of Functionality

Nasal cannula according to various embodiments of the invention may beconfigured to deliver high-flow therapeutic gases to a patient's upperairway through the patient's nose. Such gases may include, for example,air, humidity, oxygen, therapeutic gases or a mixture of these, and maybe heated or unheated. In particular embodiments of the invention, thecannula may be useful for CPAP (continuous positive airway pressure)applications, which may be useful in the treatment of sleep apnea and inproviding respiratory support to patients (e.g., after abdominalsurgery), to alleviate snoring, or for other therapeutic uses.

Nasal cannula according to particular embodiments of the inventioninclude (or are adapted to facilitate the positioning of) one or moresensors adjacent or within one or more of the cannula's nasal inserts.Accordingly, the nasal cannula may be configured so that at least aportion of one or more sensors is in place in one or both of a user'snares when the nasal cannula is operably worn by the user. This may beparticularly helpful in evaluating the environment of the internalportion of the user's nose and/or the user's upper airway. As describedin greater detail below, in various embodiments of the invention, thecannula is adapted so that it will not create a seal with the patient'snares when the cannula is in use.

Nasal cannula according to other embodiments of the invention includenozzles that are adapted to remain outside of a user's nares while thecannula is in use. Accordingly, the nozzles avoid sealing with thepatient's nares while the cannula is in use. In some embodiments, thenasal cannula include elongate extensions that are inserted into theuser's nares to detect pressure in one or both nares.

In certain embodiments of the invention, sensors are provided adjacentor within both of the nasal cannula's nasal inserts. In various otherembodiments, sensors are provided adjacent or within one or moreelongate extensions that extend into the user's nares. In variousembodiments, elongate extensions may be used in conjunction with nasalinserts or with nozzles. The use of sensors may be useful, for example,in monitoring environmental changes from one of the user's nares to theother. This information may be helpful, for example, in determining whenthe dominant flow of air changes from one of the user's nares to theother, which may affect the desired flow characteristics of therapy.Accordingly, data from each nare may provide information which may beuseful in establishing or modifying the user's treatment regimen.

Overview of Exemplary Cannula Structures

A cannula 100 according to one embodiment of the invention is shown inFIG. 1. As may be understood from this figure, in this embodiment, thecannula 100 includes a hollow, elongated tubular base portion 105 thatincludes a central portion 110, a first end portion 115, and a secondend portion 120. The first and second end portions 115, 120 may beangled relative to the central portion 110 as shown in FIG. 1.

In various embodiments of the invention, the cannula 100 includes afirst inlet 117 adjacent the outer end of the first end portion 115, anda second inlet 122 adjacent the second end portion 120 (in otherembodiments, the cannula may include only one such inlet). The cannula100 further comprises a pair of hollow, elongated, tubular nasal inserts(e.g., nasal catheters) 125, 130 that extend outwardly from the nasalcannula's base portion 105 and that are in gaseous communication withthe base portion's interior. In various embodiments, the respectivecentral axes of the nasal inserts 125, 130 are substantially parallel toeach other, and are substantially perpendicular to the central axis ofthe central portion 110 of the nasal cannula's base portion 105.

In particular embodiments of the invention, the cannula defines at leastone conduit that is adapted to guide a sensor so that the sensor isintroduced adjacent or into the interior of the cannula so that, whenthe cannula is being operably worn by a user, the environment beingmonitored by the sensor reflects that of the internal portion of theuser's nose and/or the user's upper airway. In various embodiments ofthe invention, a user may temporarily insert the sensor into or throughthe conduit to determine correct settings for the cannula system, andthen may remove the sensor after the correct settings have beenachieved. In other embodiments, the sensor may be left in place withinthe conduit for the purpose of monitoring gas data within (or adjacent)the cannula over time (e.g., for purposes of controlling the user'stherapy regimen). In a further embodiment, the sensor may be positionedadjacent an outlet of the conduit.

The sensor may be connected (e.g., via electrical wires) to a computerthat is controlling the flow of respiratory gases into the cannula. Thecomputer may use information received from the sensor to control thisflow of gas and/or other properties of the system, or may issue an alarmif the information satisfies pre-determined criteria (e.g., if theinformation indicates potentially dangerous conditions within thepatient's airway).

As may be understood from FIGS. 8A-8C, in a particular embodiment of theinvention, at least one of the cannula's conduits 850 is defined by, andextends within, a side wall of the cannula 800. Alternatively, theconduit may be disposed within an interior passage defined by thecannula. For example, one or more of the conduits may be defined by atube that is attached immediately adjacent an interior surface of thecannula (e.g., adjacent an interior surface of the cannula's baseportion, or an interior surface of one of the cannula's nasal inserts).The cannula's conduits are preferably adapted for: (1) receiving a flowof gas at one or more inlets that are in communication with the conduit,and (2) guiding this flow of gas to an outlet in the cannula. In variousembodiments, one or more of the inlets is defined within an exteriorportion of one of the cannula's nasal inserts.

As may be understood from FIG. 1, in various embodiments of theinvention, each of the cannula's conduit outlets 136, 141 is located atthe end of a respective elongate, substantially tubular, outlet member135, 140. For example, in the embodiment shown in FIG. 1, the cannula100 includes a first outlet member 135 that is substantially parallel tothe cannula's first nasal insert 125. In this embodiment, the firstoutlet member 135 and the first nasal insert 125 may be positioned onopposite sides of the nasal cannula's base portion 105 as shown inFIG. 1. Similarly, in a particular embodiment of the invention, thecannula 100 includes a second outlet member 140 that is substantiallyparallel to the cannula's second nasal insert 130. The second outletmember 140 and second nasal insert 130 are also preferably positioned onopposite sides of the nasal cannula's base portion 105.

In various embodiments of the invention, a sensor (e.g., a pressure,temperature, or O₂ sensor) is provided adjacent at least one of (andpreferably each of) the cannula's outlets 136, 141 and is used tomeasure the properties of gas from that outlet 136, 141. In a furtherembodiment of the invention, accessory tubing is used to connect eachoutlet 135, 140 with at least one corresponding sensor (and/or at leastone external monitoring device) that may, for example, be spaced apartfrom the cannula 100.

In yet another embodiment of the invention, one or more sensors areprovided within the conduit, and used to measure the properties of gasaccessed through the conduit. In this embodiment, information from eachsensor may be relayed to a control system outside the cannula via, forexample, an electrical wire that extends from the sensor and through theoutlet 135, 140 of the conduit in which the sensor is disposed.

In alternative embodiments of the invention, each of the cannula'sconduits may extend: (1) from the inlets 152, 154; (2) through, oradjacent, a side wall of one of the cannula's nasal inserts 125, 130;(3) through, or adjacent, a side wall of the cannula's body portion 105;and (4) to an outlet 135, 140 that is defined within, or disposedadjacent, the cannula's body portion 105. In one such embodiment, theconduit comprises a substantially tubular portion that is disposedadjacent an interior surface of the cannula's body portion.

As may be understood from FIG. 2, in certain embodiments of theinvention, the cannula 200 includes at least one sensor 245 that isintegrated into an exterior portion of the cannula 200 (e.g., within arecess 223 formed within an exterior surface of one of the cannula'snasal inserts 225, 230). In this embodiment, information from the sensor245 may be relayed to a control system outside the cannula 200 via anelectrical wire 246 that extends from the sensor 245, through a conduit,and out an outlet 235, 240 in the conduit. In various embodiments of theinvention, the conduit extends through or adjacent an interior portionof a side wall of one of the cannula's nasal inserts 225, 230 and/orthrough or adjacent an interior portion of a side wall of the cannula'sbody portion 205.

In particular embodiments of the invention, at least one sensor 245 isfixedly attached to the cannula 100 so that it may not be easily removedby a user. Also, in particular embodiments, at least one sensor 245 isdetachably connected adjacent the cannula 100 so that the sensor 245 maybe easily detached from (and, in certain embodiments, reattached to) thecannula 100.

The cannula 1000 includes a hollow, elongated tubular base portion 1005that includes a central portion 1010, a first end portion 1015, and asecond end portion 1020. The first and second end portions 1010, 1015may be angled relative to the central portion 1010, as shown in FIG. 10.In various embodiments of the invention, the cannula 1000 includes afirst inlet 1017 adjacent the outer end of the first end portion 1015,and a second inlet 1022 adjacent the outer end of the second end portion1020.

The cannula 1000 further comprises a pair of hollow, elongated, tubularnozzles (a first nozzle 1026 and a second nozzle 1031) that extendoutwardly from the nasal cannula's base portion 1005. In variousembodiments, the respective central axes of the nozzles 1026, 1031 aresubstantially parallel to each other and are substantially perpendicularto the central axis of the central portion 1010 of the nasal cannula'sbase portion 1005. In various embodiments, the nozzles 1026, 1031 defineconduits that are in gaseous communication with the interior of thecannula's base portion 1005. In particular embodiments of the invention,the first and second nozzles 1026, 1031 are adapted to be positionedoutside of a user's nares while the cannula is in use. In particularembodiments, the nozzles 1026, 1031 each define a respective nozzleoutlet. For example, the first nozzle 1026 defines a first nozzle outlet1083, and the second nozzle 1031 defines a second nozzle outlet 1084. Invarious embodiments, when the nasal cannula 1000 is operativelypositioned adjacent a user's nares, each of the nozzle's outlets 1083,1084 is positioned to direct a focused flow of gas into a correspondingone of the user's nares.

In alternative embodiments, such as the embodiment shown in FIG. 12, thenasal cannula 1200 may include a single nozzle 1227 that defines aconduit or air passageway that is in gaseous communication with aninterior portion of the cannula's base portion 1205. As described ingreater detail below, in various embodiments, the nozzle 1227 extendsoutwardly from the cannula's base portion 1205 and has an oblong, orelliptical, cross-section. In this and other embodiments, the nozzle1227 is shaped to deliver a focused flow of gas simultaneously into bothof a user's nares when the cannula 1200 is in use.

In various embodiments, the nasal cannula includes one or more elongateextensions that are adapted for insertion into one or more of the user'snares. For example, returning to the embodiment shown in FIG. 10, thenasal cannula 1000 may include multiple elongate extensions (for examplea first elongate extension 1070 and a second elongate extension 1072)that are long enough to allow each of the elongate extensions 1070, 1702to be inserted into a respective one of the user's nares while the nasalcannula 1000 is in use. In various embodiments, each of the elongateextensions 1070, 1072 may have a central axis that runs substantiallyparallel to the central axis of a corresponding nozzle 1026, 1031. Forexample, as can be understood from FIG. 10, in certain embodiments, afirst elongate extension 1070 has a central axis that lies substantiallyparallel to and below the central axis of a corresponding first nozzle1026, when the nasal cannula is operatively positioned adjacent a user'snares. Similarly, in various embodiments, a second elongate extension1072 has a central axis that lies substantially parallel to and belowthe central axis of a corresponding second nozzle 1031, when the nasalcannula 1000 is operatively positioned adjacent a user's nares. Invarious other embodiments, the elongate extensions may lie within, andextend outwardly from, their corresponding nozzles 1070, 1072.

As a further example, FIG. 12 illustrates an exemplary nasal cannula1200 having multiple elongate extensions (a first elongate extension1270 and a second elongate extension 1272), which both lie substantiallybelow a single nozzle 1227 when the nasal cannula 1200 is in anoperative position adjacent the user's nose. In some embodiments, thecentral axes of the first and second elongate extensions 1270, 1272, maybe substantially parallel to the central axis of the nozzle 1227. Also,in various embodiments, one or both of the elongate extensions 1270,1272 may lie within the nozzle 1227. In this and other embodiments, adistal end of each of the elongate extensions 1270, 1272 may extendbeyond a distal end of the nozzle 1227.

As described above, in certain embodiments of the invention, the nasalcannula includes one or more sensors that are adapted to measure gasdata (e.g., gas pressure) within the user's nares while the nasalcannula is in use. For example, the nasal cannula 1000 shown in FIG. 10may include a sensor positioned adjacent the distal end of one or bothof the first and second elongate extensions 1070, 1072. In variousembodiments, each elongate extension may be adapted to: (1) support asensor adjacent (e.g., at) the distal end of the elongate extension; and(2) support a wire that is simultaneously connected to the sensor and acontrol mechanism that is adapted to adjust the properties of gasflowing through the cannula 1000.

In other embodiments, the elongate extensions define conduits. Forexample, the sensor(s) may be positioned within the interior or exteriorof the elongate extensions and information from the sensor(s) may berelayed to a control system via a wire extending through a conduit (forexample, conduit 1023 of FIG. 10) or passageway defined by each of theelongate extensions. In one embodiment, as shown, for example, in FIG.10, the conduit 1023 is shaped similarly to the nasal cannula's baseportion 1005, and lies substantially below the base portion 1005 whenthe nasal cannula 1000 is operatively in use. In various embodiments,the conduit 1023 is positioned within the base portion 1005 such thatthe first and second elongate extensions 1070, 1072 lie within, andextend outwardly from, the respective first and second nozzles 1026,1031.

In various embodiments, each elongate extension defines a respectiveconduit that can serve as an air passageway. For example, in certainembodiments, each conduit is adapted to provide a passage that permitsgaseous communication between a user's nares and a control system orother device for measuring and adjusting the properties of the air. Inthis and other embodiments, a sensor may be positioned at the controlbox to measure the properties (e.g., pressure) of air in the user'snares. In some embodiments, the elongate extensions define a conduitthat serves both as an air passageway as well as a conduit for allowinga wire to pass from a sensor positioned adjacent the tip of the elongateextension to the control system or other device.

Data Monitored by Sensors

In various embodiments of the invention, such as those described above,one or more sensors may be positioned to measure gas data within aninterior portion of one of the nasal cannula's conduits, or to measuregas data adjacent an exterior portion of the cannula. In suchembodiments, one or more sensors may be, for example, positionedadjacent an interior or exterior surface of the cannula. In certainembodiments of the invention, one or more of the cannula's sensors isadapted to monitor one or more of the following types of data within thecannula's conduits, or adjacent the cannula's exterior surface (e.g.,adjacent a side portion, or distal end of, one of the cannula's nasalinserts): (1) gas pressure; (2) gas flow rate; (3) carbon dioxidecontent; (4) temperature; (5) moisture level; and/or (6) oxygen content.

Absolute vs. Relative Pressure Measurements

In various embodiments of the invention, the cannula may be configuredfor sensing absolute pressure within, or adjacent, a particular portionof the cannula. Similarly, in particular embodiments, the cannula may beconfigured to measure the difference between the pressure at twodifferent locations within the cannula. This may be done, for example,by providing two separate sensors (e.g., that are positioned indifferent locations within one of the cannula's conduits), or byproviding two physically distinct gas intake conduits, each of which isadapted for routing gas from a different location within the cannula.For example, in various embodiments of the invention shown in FIG. 1,the first inlet 152 may be connected to a first intake conduit that isadapted for routing gas to a first sensor, and the second inlet 154 maybe connected to a physically separate second intake conduit that isadapted for routing gas to a second pressure sensor. Information fromthe first and second sensors may then be used to calculate thedifference in pressure between the first and second inlets 152, 154.Alternatively, a differential pressure sensor may be used.

Suitable Sensors

Suitable sensors for use with various embodiments of the inventioninclude electronic and optical sensors. For example, suitable sensorsmay include: (1) Disposable MEM Piezoelectric sensors (e.g., from SilexMicrosensors); (2) light-based sensors such as a McCaul O₂ sensor—seeU.S. Pat. No. 6,150,661 to McCaul; and (3) Micro-pressure sensors, suchas those currently available from Honeywell.

Non-Sealing Feature

As shown in FIG. 4, in various embodiments of the invention, one or moreof the nasal cannula's nasal inserts 425, 430 defines one or morerecesses 423 (e.g., grooves, semicircular recesses, or otherindentations or conduits) that extend along a length of the nasalinsert's exterior surface. As may be understood from this figure, invarious embodiments of the invention, at least one of these recesses 423is an elongate groove that extends from adjacent a distal surface of thenasal insert 325, 330, 425, 430 and past the midpoint between: (1) thenasal insert's distal surface and (2) the portion of the nasal insert425, 430 that is immediately adjacent the nasal cannula's base portion305, 405. As may also be understood from this figure, in variousembodiments of the invention, each groove 423 extends substantiallyparallel to the central axis of its respective nasal insert 425, 430.

In particular embodiments of the invention, such as the embodiment shownin FIG. 4, at least one of the nasal cannula's nasal inserts 425, 430 isconfigured so that when the nasal inserts 425, 430 are operativelypositioned within a user's nares, the nasal inserts do not form anairtight seal with the user's nares. This may be due, for example, tothe ability of air to flow adjacent the user's nare through recesses 423in the nasal inserts 425, 430 when the user is wearing the nasalcannula.

FIGS. 5-8 depict additional embodiments of the invention that areconfigured so that when the cannula's nasal inserts are operativelypositioned adjacent (e.g., partially within) the user's nares, the nasalinserts do not form a seal with the user's nares. For example, in theembodiment shown in FIG. 5, at least one (and preferably both) of thecannula's nasal inserts 525, 530 comprise an inlet 555 (which may, forexample, be substantially tubular), and one or more flange portions 560,561 that are adapted to maintain a physical separation between anexterior side surface of the inlet 555 and a user's nare when the nasalinsert 525, 530 is inserted into the user's nare.

For example, in the embodiment of the invention shown in FIG. 5, each ofthe cannula's nasal inserts 525, 530 includes a substantially tubularinlet 555 and a pair of co-facing, elongated flanges 560, 561 that eachhave a substantially C-shaped cross section. In this embodiment, theseC-shaped flanges 560, 561 cooperate with a portion of the exterior ofthe inlet 555 to form a substantially U-shaped channel (which is oneexample of a “nasal lumen”) through which ambient air may flow to and/orfrom a user's nasal passages when the cannula 500 is operatively inplace within the user's nares. In this embodiment, when the nasalinserts 525, 530 are properly in place within the user's nares,respiratory gas is free to flow into the -user's nose through the inlet555, and ambient air is free to flow into and out of the user's nosethrough a passage defined by: (1) the flanges 560, 561; (2) the exteriorside surface of the inlet 555 that extends between the flanges 560, 561;and (3) an interior portion of the user's nose. In various embodiments,air may flow to and/or from a user's nose through this passage when thecannula 500 is operatively in place within the user's nares. A pathway(e.g., a semicircular pathway) may be provided adjacent the interior endof this U-shaped channel, which may act as a passageway for gas exhaledand inhaled through the U-shaped channel.

The general embodiment shown in FIG. 5 may have many differentstructural configurations. For example, as shown in FIG. 6, whichdepicts a cross section of a nasal insert according to a particularembodiment of the invention, the respiratory gas inlets of the cannula'snasal inserts 655 may be in the form of a tube having an irregular crosssection (e.g., a substantially pie-piece-shaped cross section) ratherthan a circular cross section. Alternatively, as may be understood fromFIG. 7, the respiratory gas inlets of the cannula's nasal inserts 755may be in the form of a tube having a substantially half-circular crosssection rather than a circular cross section.

Similarly, as may be understood from FIGS. 6 and 7, the shape and sizeof the cannula's flanges may vary from embodiment to embodiment. Forexample, in the embodiment shown in FIG. 6, each of the flanges 660, 661has a relatively short, substantially C-shaped cross section and thedistal ends of flanges 660, 661 are spaced apart from each other to forma gap. As shown in FIG. 7, in other embodiments, each of the flanges760, 761 may have a relatively long, substantially C-shaped crosssection and the distal ends of the flanges 760, 761 may be positionedimmediately adjacent each other.

As may be understood from FIG. 7, in various embodiments of theinvention, a separation 763 (e.g., a slit, such as an angular slit) isprovided between the flanges 760, 761. This may allow the flanges 760,761 to move relative to each other and to thereby conform to the nare inwhich the nasal insert is inserted. In other embodiments, the crosssection of the nasal inserts is substantially as that shown in FIG. 7,except that no separation 763 is provided within the semi-circularflange portion. Accordingly, in this embodiment of the invention, asubstantially semi-circular portion of the exterior of the air inletcooperates with a substantially semi-circular portion of the flangeportion to form an exterior having a contiguous, substantially circularcross section. One such embodiment is shown in FIGS. 8A-8C.

As may be understood from FIGS. 8A-8C, in this embodiment, when thecannula 800 is in use, respiratory gas may flow into the user's nosethrough passageways 881 (e.g., a portion of which may be defined by acorresponding respiratory gas inlet 855) that extend through each of thecannula's nasal inserts 825, 830. A pathway 885 of substantiallysemi-circular cross section extends between the distal end of each nasalinsert 825, 830 to a substantially semicircular outlet 865 definedwithin the cannula's base 805. In various embodiments, when the cannula800 is in use, the user may inhale and exhale gas through this pathway885.

In certain embodiments, as discussed above, a conduit 850 is provided ineach of the cannula's nasal inserts 825, 830 (see FIG. 8C). Each ofthese conduits 850 may be adapted to: (1) receive gas from the interiorof a corresponding pathway 885 and/or from adjacent the exterior of oneof the cannula's nasal inserts 825, 830, and (2) guide the gas out of acorresponding outlet 835, 840 in the cannula 800. As discussed above,one or more sensors may be disposed within, or adjacent, the conduit 850and used to assess one or more attributes of gas flowing through oradjacent the conduit 850.

It should be understood that the embodiments of the invention shown inFIGS. 4-8 and related embodiments may have utility with or without theuse of sensors or sensor conduits. It should also be understood that thevarious nasal inserts may be configured to be disposed in anyappropriate orientation within the user's nares when the cannula isoperably positioned within the user's nares. For example, in oneembodiment of the invention, the cannula may be positioned so that thecannula's nasal lumen is immediately adjacent, or so that it facesanterior-laterally away from, the user's nasal spine.

Turning to yet another embodiment of the invention, as shown in FIG. 9,the cannula 900 and corresponding sensor may be adapted so that a tubeinlet 970, 972 for at least one sensor (or the sensor itself) ismaintained adjacent, and spaced a pre-determined distance apart from,the distal end of a respective nasal insert 925, 930. In thisembodiment, the sensor (or sensor intake inlet) may be spaced apart fromthe rest of the nasal cannula 900 adjacent one of the nasal cannula'soutlet openings.

As may be understood from FIG. 10, in various embodiments, the first andsecond nozzles 1026, 1031 of the nasal cannula are configured to remainoutside of the user's nares while the cannula is in use. For example,the nozzles may be of a length such that, when the cannula is in use,the distal ends of the nozzles 1026, 1031 lie adjacent, but outside, theuser's nares. By preventing insertion of the nozzles 1026, 1031 into thenares, sealing of the nares can be avoided. As may be understood fromFIG. 13, in various embodiments, when the nasal cannula is in anoperative position adjacent the user's nares, an outlet portion (anddistal end) of each nozzle 1326, 1331 is spaced apart from, andsubstantially in-line (e.g., substantially co-axial) with, acorresponding one of the patient's nares. In various embodiments, whenthe nasal cannula is operatively in use, the outlet of each nozzle isspaced apart from the patient's nares and each nozzle is positioned todirect a focused flow of gas into a particular respective one of theuser's nares.

As may be understood from FIG. 11, in particular embodiments, a stop1190 may extend outwardly from the base portion 1105 of the nasalcannula. In some embodiments, the stop 1190 lies in between the firstand second nozzles 1126, 1131 and defines a central axis that runssubstantially parallel to the respective central axes of the nozzles1126, 1131. The stop 1190, in some embodiments, may extend outwardlyfrom the nasal cannula's base portion 1105 a length greater than that ofthe nozzles 1126, 1131. In this manner, the stop 1190 prevents thenozzles 1126, 1131 from being inserted into the user's nares when thenasal cannula 1100 is in use.

For example, the stop 1190 may be positioned so that when the nasalcannula 1100 is in use, the stop is designed to engage the columella ofthe user's nose and thereby prevent the nozzles 1126, 1131 from beinginserted into the user's nares. In various embodiments, the first andsecond nozzles 1126, 1131 are positioned on either side of the stop 1190so that when the nasal cannula 1100 is operatively in use, the eachnozzle 1126, 1131 will be spaced apart from a respective particular oneof the patient's nares and will be positioned to direct a focused flowof gas into that particular nare by, for example, being positioned sothat the outlet (and distal end) of each nozzle (first outlet 1183 andsecond outlet 1184) is substantially in-line (e.g., substantiallyco-axial) with, a corresponding one of the patient's nares.

As may be understood from FIG. 12, in various embodiments, the nasalcannula 1200 may include only a single nozzle 1227. The nozzle 1227, invarious embodiments, has an oblong or substantially ellipticalcross-section. In these embodiments, the major axis of the ellipse runssubstantially parallel to the central axis of the base portion 1205 ofthe nasal cannula. In one embodiment, the nozzle 1227 is wide enough toallow air to flow into both of a user's nares when the nasal cannula isin use. For example, in various embodiments, the width of the nozzle1227 (e.g., a length defined by the major axis of the nozzle'selliptical cross section) may be approximately equal to (or greaterthan) the total width of the user's nares.

As may be understood from FIG. 14, when the nasal cannula 1400 isoperatively in use, a first lateral side 1430 of the nozzle outlet 1429is spaced apart from, and adjacent, a user's first nare, and a secondlateral side 1430 of the nozzle 1429 is spaced apart from, and adjacent,the user's second nare. In this and other configurations, the nozzle1422 is configured to direct a focused flow of gas simultaneously intoeach of the user's nares. In various embodiments, when the nozzle is ofa width approximately equal to (or greater than) the total width of theuser's nares, and other widths, the nozzle 1227 is sufficiently wide toprevent the nozzle 1227 from being inserted into a user's nare, thuspreventing sealing of the nasal cannula with the nare.

In various other embodiments, the cannula's single nozzle may have adifferent cross-section that is not oblong or elliptical. For example,the nozzle may have a substantially circular cross-section, with adiameter that is wide enough to allow air to flow into both of a user'snares when the cannula is in use, while simultaneously being wide enoughto prevent insertion into a single nare. In various other embodiments,the nasal cannula may have more than one nozzle, each having asubstantially oblong cross section and a width that prevents insertioninto each of a user's nares.

In various embodiments, one or more of the cannula's elongate extensionshas a diameter that is adapted to prevent sealing with the user's nares.For example, the elongate extension(s) may have a diameter that issubstantially narrower than a user's nares, so that sealing is avoided.In other embodiments, the elongate extension(s) may include featuressuch as grooves or recesses, as described above, to prevent sealing wheninserted into a user's nare(s).

Exemplary Use of the Cannula

To use a cannula according to a particular embodiment of the invention,a physician or technician may have a patient use the cannula for a briefperiod of time, while the physician or technician monitors informationreceived from the cannula's various sensors, or the information may berecorded for later analysis. The physician or technician may then usethis information to adjust the structure or operation of the cannulauntil the cannula's sensors indicate that the patient's upper airwayenvironment satisfies certain conditions.

Similarly, in various embodiments, the cannula's sensors may be used tomonitor conditions within the patient's upper airway over time. In aparticular embodiment, the cannula's sensors may be connected to acontrol system that will automatically alter or modify the flow oftherapeutic gas into the cannula if information from the sensorindicates undesirable conditions within the patient's upper airway. Infurther embodiments of the invention, the sensor is connected to acontrol system that issues an alarm if information from the cannula'ssensors indicate undesirable conditions within the patient's airway.

FIGS. 13 and 14 depict various embodiments of nasal cannulas being usedon a patient. As may be understood from FIG. 13, for example, a nasalcannula is used on a young or small infant for high flow therapy. Forexample, a nasal cannula similar to that shown in FIG. 10 can be used.In various embodiments, first and second elongate extensions 1370, 1372are inserted into the patient's nares, while corresponding first andsecond nozzles 1326, 1331 remain adjacent and external to the patient'snares. As may be appreciated, when the nasal cannula is in use, airflows into the patient's nares via the nozzles. FIG. 14 depicts oneembodiment of a nasal cannula in use on a patient. In one embodiment, anasal cannula such as that shown in FIG. 12 can be used. As may beunderstood from FIG. 14, a nasal cannula having a single nozzle 1427 canbe used, in which the nozzle is sized and shaped (e.g., is ellipticaland/or wider than a patient's nare) to prevent insertion into thepatient's nares. In various other embodiments, nasal cannula havingnasal inserts, as described throughout, can be used. In theseembodiments, the nasal inserts are inserted into the user's nares whilethe cannula is in use. Nasal cannula according to embodiments of theinvention can be used on a variety of patients.

CONCLUSION

Many modifications and other embodiments of the inventions set forthherein will come to mind to one skilled in the art to which theseinventions pertain having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the inventions are not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims. Forexample, although the embodiment shown in FIG. 1 shows each nasal insert125, 130 having a two inlets 152, 154, in alternative embodiments of theinvention, one or more of the nasal inserts 125, 130 may have more orless than two inlets (and/or more or less than two sensors). Althoughspecific terms are employed herein, they are used in a generic anddescriptive sense only and not for purposes of limitation.

1. A nasal cannula comprising: a base portion defining a firsttherapeutic gas passageway; a nasal insert disposed adjacent said baseportion and defining a second therapeutic gas passageway, said firsttherapeutic gas passageway being in gaseous communication with saidsecond therapeutic gas passageway; and at least one sensor for measuringthe properties of gas adjacent said nasal insert.
 2. The nasal cannulaof claim 1, wherein said nasal insert further defines an elongatedconduit that is adapted to route gas from adjacent an exterior portionof said nasal insert and through said conduit and to said sensor.
 3. Thenasal cannula of claim 2, wherein said at least one sensor is disposedwithin said conduit.
 4. The nasal cannula of claim 2, wherein: saidnasal cannula defines an outlet for said conduit; and said sensor isdisposed adjacent said outlet.
 5. The nasal cannula of claim 1, wherein:said nasal insert is a first nasal insert; said at least one sensorcomprises a first sensor; said data is a first set of data; and saidnasal cannula comprises: a second nasal insert disposed adjacent saidbase portion and defining a third therapeutic gas passageway, said thirdtherapeutic gas passageway being in gaseous communication with saidfirst therapeutic gas passageway, and a second sensor for measuring theproperties of gas adjacent said second nasal insert.
 6. A nasal cannulacomprising: a base portion defining a first interior portion; a nasalinsert disposed adjacent said base portion and defining a secondinterior portion, said first interior portion being in gaseouscommunication with said second interior portion; wherein: said nasalinsert defines a passage that is adapted to guide a sensor between: (a)a first position in which the sensor is outside said cannula, and (b) asecond position in which the sensor is positioned to monitor gas dataadjacent an exterior portion of said cannula.
 7. A nasal cannulacomprising: a base portion defining a first interior portion; a nasalinsert disposed adjacent said base portion and defining a secondinterior portion, said first interior portion being in gaseouscommunication with said second interior portion, wherein: said nasalinsert defines a recess that is adapted to prevent said nasal insertfrom creating a seal with a user's nare when the nasal insert isoperatively positioned within said nare.
 8. The nasal cannula of claim7, wherein said recess comprises an elongate groove.
 9. The nasalcannula of claim 7, wherein said recess comprises an elongate channel.10. A nasal cannula comprising: a base portion defining a first interiorportion; a nasal insert disposed adjacent said base portion and defininga second interior portion, said first interior portion being in gaseouscommunication with said second interior portion, wherein: said nasalinsert defines a passageway that is adapted to prevent said nasal insertfrom creating a seal with a user's nare when the nasal insert isoperatively positioned within said nare, said passageway beingdimensioned to: (1) allow the user to inhale ambient air through saidpassageway, when said nasal insert is operatively positioned within saidnare; and (2) to allow the user to exhale air through said passagewaywhen said nasal insert is operatively positioned within said nare. 11.The nasal cannula of claim 10, wherein said nasal cannula furthercomprises at least one sensor that is configured for determining theinternal environment of the user's upper airway for continuous positiveairway pressure.
 12. The nasal cannula of claim 10, wherein said nasalcannula further comprises at least one sensor that is configured fordetermining the internal environment of the user's upper airway for highflow respiratory support.
 13. The nasal cannula of claim 10, whereinsaid nasal cannula further comprises at least one sensor that isconfigured to transmit data to a control system that is adapted for: (A)receiving data from said at least one sensor; and (B) adjusting thedelivery of respiratory gas to said nasal cannula based on said data.14. The nasal cannula of claim 10, wherein said nasal cannula furthercomprises at least one sensor that is configured to transmit data to acontrol system that is adapted for receiving data from said at least onesensor and for issuing an alarm in response to said data satisfyingpre-determined criteria.
 15. A nasal cannula comprising: a supply tubedefining an interior portion; a nasal insert defining a therapeutic gaspassageway that is in gaseous communication with said interior portionof said supply tube; and at least one sensor for measuring theproperties of gas adjacent said nasal insert.
 16. A nasal cannulacomprising: a base portion defining a first therapeutic gas passageway;at least one nozzle disposed adjacent said base portion and defining asecond therapeutic gas passageway, said first therapeutic gas passagewaybeing in gaseous communication with said second therapeutic gaspassageway, said at least one nozzle adapted to provide a directed flowof therapeutic gas from said second therapeutic gas passageway and intoa particular one of a user's nares when said nasal cannula isoperatively positioned adjacent said user's nares; and an elongateextension disposed adjacent said nozzle, wherein: said nasal cannula isadapted so that, when said nasal cannula is operatively positionedadjacent said user's nares: said at least one nozzle is spaced apartfrom said particular one of said user's nares; and said elongateextension extends into an interior portion of said particular one ofsaid user's nares.
 17. The nasal cannula of claim 16, wherein said nasalcannula further comprises at least one sensor for measuring theproperties of gas within at least one of a user's nares.
 18. The nasalcannula of claim 16, wherein said at least one nozzle is sized andshaped to prevent insertion into a user's nare when said at least onenozzle is operatively positioned adjacent said nare.
 19. The nasalcannula of claim 16, further comprising a stop disposed adjacent saidbase portion, wherein said stop is positioned to engage a user'scolumella and prevent insertion of said nozzle into a user's nare whensaid nozzle is operatively positioned adjacent said nare.
 20. The nasalcannula of claim 16, wherein said elongate extension lies within saidsecond gas passageway and wherein a distal end of said elongateextension extends beyond a distal end of said nozzle.
 21. The nasalcannula of claim 16, wherein said at least one sensor is disposedadjacent a distal end of said elongate extension.
 22. A nasal cannulacomprising: a base portion defining a first gas passageway; a nozzledisposed adjacent said base portion and defining a second therapeuticgas passageway, said first gas passageway being in gaseous communicationwith said second gas passageway, said nozzle being sized and shaped toprevent insertion into a user's nare when said nozzle is operativelypositioned adjacent said nare; an elongate extension disposed adjacentsaid nozzle and defining a third passageway; and at least one sensor formeasuring the properties of gas adjacent a distal end of said elongateextension.
 23. The nasal cannula of claim 22, wherein a distal end ofsaid elongate extension is adapted to be disposed adjacent a particularone of said user's nares when said nasal cannula is operativelypositioned adjacent said user's nares.
 24. The nasal cannula of claim22, wherein a distal end of said elongate extension is adapted to bedisposed within a particular one of said user's nares when said nasalcannula is operatively positioned adjacent said user's nares.
 25. Thenasal cannula of claim 24, wherein said sensor is disposed within saidelongate extension.
 26. A nasal cannula comprising: a base portiondefining a first gas passageway; at least one nozzle disposed adjacentsaid base portion and defining a second gas passageway, said first gaspassageway being in gaseous communication with said second gaspassageway, said at least one nozzle adapted to provide a directed flowof therapeutic gas from said second therapeutic gas passageway and intoa particular one of a user's nares when said nasal cannula isoperatively positioned adjacent said user's nares; and a stop disposedadjacent said base portion, wherein said stop is positioned to engage auser's columella and prevent insertion of said nozzle into saidparticular one of said user's nares when said nozzle is operativelypositioned adjacent said user's nares.
 27. The nasal cannula of claim26, wherein: said nasal cannula further comprises an elongate extensiondisposed adjacent said nozzle; and said nasal cannula is adapted sothat, when said nasal cannula is operatively positioned adjacent auser's nares, said elongate extension extends into an interior of saidparticular one of said user's nares.
 28. The nasal cannula of claim 27,further comprising at least one sensor for measuring the properties ofgas adjacent said elongate-extension.
 29. The nasal cannula of claim 28,wherein a distal end of said elongate extension extends beyond a distalend of said nozzle.
 30. A system for delivering therapeutic gas to auser, said system comprising: a nasal cannula that comprises: a baseportion defining a first therapeutic gas passageway, a nasal insertdisposed adjacent said base portion and defining a second therapeuticgas passageway, said first therapeutic gas passageway being in gaseouscommunication with said second therapeutic gas passageway, and at leastone sensor for measuring the properties of gas adjacent said nasalinsert; and a therapeutic gas delivery control system that is adapted toreceive data from said at least one sensor, and to adjust a flow ofrespiratory gas to said nasal cannula based, at least in part, on saiddata.
 31. The system of claim 30, wherein: said therapeutic gas deliverycontrol system is further adapted for adjusting a flow of respiratorygas through said first and second passageways based on said data. 32.The system of claim 30, wherein: said nasal insert defines a recess thatis adapted to prevent said nasal insert from creating a seal with a nareof said user when the nasal insert is operatively positioned within saidnare.
 33. The nasal cannula of claim 32, wherein said recess comprisesan elongate groove.
 34. The nasal cannula of claim 32, wherein saidrecess comprises an elongate channel.
 35. The system of claim 30,wherein: said nasal insert is a first nasal insert; said at least onesensor comprises a first sensor; said data is a first set of data; andsaid nasal cannula comprises: a second nasal insert disposed adjacentsaid base portion and defining a third therapeutic gas passageway, saidfirst therapeutic gas passageway being in gaseous communication withsaid third therapeutic gas passageway, and a second sensor for measuringthe properties of gas adjacent said second nasal insert.
 36. The systemof claim 35, wherein: said therapeutic gas delivery control system isadapted for: receiving a second set of data from said second sensor, andadjusting said flow of respiratory gas to said nasal cannula, at leastin part, based on said second set of data.
 37. The system of claim 36,wherein said first set of data is a different type of data than saidsecond set of data.
 38. The system of claim 36, wherein said firstsensor is a different type of sensor than said second sensor.